APPLICANT'S ABSTRACT: The UCLA Drug Abuse Research Center is submitting this proposal for a three- year project to conduct a meta-analysis of the effectiveness of drug abuse treatment, modalities, and services. Although review articles have summarized the findings of research studies on drug treatment, it is often difficult to arrive at definitive conclusions when a large number of studies, often with ambiguous or inconsistent results, are involved. Also, none of the reviews of drug treatment has provided quantitative estimates of the average effect size, or the magnitude, of treatment. This project has the following specific aims: (1) To compile a comprehensive database and document library of studies evaluating drug abuse treatment published since 1965 in order to provide the basis for a meta-analysis of the effectiveness of drug treatment modalities, programs, and services. (2) To describe the current state of research on drug treatment effectiveness in the United States with regard to such issues as research organizations, methodology and design, types of programs and services evaluated, outcome measures, publication outlets, and trends over time. (3) To determine the overall average effect size of treatment for drug abuse, during and after treatment, and according to program modality and types of services. (4) To assess the degree to which methodological characteristics (e.g., study design quality) influence the effect size of drug treatment. (5) To assess the degree to which client and treatment characteristics (e. g. , gender, addiction severity, type of treatment, duration of treatment, follow-up period, type of funding, local context) influence the effect size of drug treatment. (6) To develop a set of reports, publications, and presentations that will disseminate the findings of the project to researchers, service providers, and policy makers. The proposed project will use meta-analytic techniques, including random effects models, to cumulate effect sizes across studies and to identify factors associated with treatment effects. The project will also examine effect sizes along various dimensions, such as treatment levels (e.g., modalities, service components) and duration of treatment, which are critical for the development of treatment policy, treatment improvement strategies, and cost-benefit analyses. The main procedural steps in the project include finalization of research design; literature search, retrieval, and selection; development and application of coding procedures; data analysis, using descriptive and inferential statistics; data interpretation and report writing; and dissemination of findings. An advisory panel consisting of specialists in drug treatment, meta- analysis, and random effects modeling will assist research staff in attending to salient treatment issues and to conducting appropriate analyses.